Electric heating device



A. F. BERRY. ELECTRIC HEATING DEVICE. APPLICATION FIlED DEC.26, 1912.RENEWED SEPT. 8, 1920.

'l,378,5 1 5. Patented y 17, 1921.

Fi Z /0 x; 2 H v I [Q Q Q Q Q QQ /5 h; 16 F /'4 Inventor Arthur FrancisBerry,

His Attorneg.

- ARTHUR FRANCIS BERRY, OF LONDON, ENGLAND, ASSIGNOR COMPANY, ACORPORATION I OF NEW YORK.

UNITED STATES PAATVE Nr' OFFICE.

T0 GENERA]; ELECTRIC ELECTRIC IiEATING DEVICE.

To alZ'wko'in it may concern: I

Be it known that I, ARTHUR FRANCIS BERRY, a subject of the King of GreatBritain, residing at London, Englanchhave invented certain new anduseful Improvements in Electric Heating Devices, (if which the followingis a specification.

This invention has reference to electrical heaters of the kindcomprising perforated plates or grids and bare resistance elementsarranged beneath the same, and designed for heating or boiling water,for cooking and the like purposes, and. it has for its object theprovision of electrical heating apparatus of this kind having greatereificiency, utility and durability than such apparatus as heretoforeconstructed.

For this purpose an electric heater made in accordance with my invent oncomprises a metal plate having comparatively large openingsseparated byribs or bars, and, a

' bare resistance elemelit i hat. inay-be bent t6 a coiled, zig-zag orequivalent-shape and is carried by' and below the plate by holders ofinsulatingmaterial secured to the ribs or bars which are constructed insuch a manner as toshielcl the holders and adjacent portions of theresistance element from contact Fig. 3 is a section on the line 3 3 ofFig. 2; Fig. 4 is a view similar to Fig. 2,'but par' with liquid thatmay boil over from the ves- .sel being heated, or which may becomespilled therefrom in any way, so that deterioration of the insulatingquality of the holders andrapid destruction of the holders and of theadjacentfportions of the resistance element shall be prevented and theefli-.

ciencyand durabilit of the heating unit maintained. The res stanceelement may be connected at different points along its length toterminals combined with a switch so that one, two or more sections ofthe element y be used at will to varythe heating efi'ect groduced, tosuit requirements.

" In the accompanying illustrative draw' ings, Figure 1 is a plan viewof an. electric heating device embodying my invention; Fig. 2 is asection on the line 22 of Fig. 1;

tially in elevation showing a slightly'modi fied form of support for theheating ele ment; F igfio is a detail view of a section of an insulatingsupporting strip and Figs. 6,

'7 and 8 are detail views of modifications.

Referring now to the drawings, a-plate 10 is provided with openings 11which are prefbe unevenly I Specification of Letters Patent. I PatentedMay 17, 1921, 1 Application filed December 26, 1917, SeriaI No. 208,782.Renewed September 8, 1920. Serial No. 409,032.

erabliyg sector shaped and separated by ribs 12. ported, beneath theplate by the ribs, from which the same is insulated. The resistanceelement .which may be helically' wound, is formed into severalconvolutions which may spaced apart as described in my British Patent#467 2 of 1909, so as to insure the plate being uniformly heated.Theresistance element .is supported by insulating strips 14 verticallydisposed and preferably formed of micat Thesestrips are fixed inrecesses 15 formed on the underside of the plate beneath the ribs.

The strips are preferably secured in position by wedges 16 (see Fig. 3)ohe on either bare resistance element 13 is supside of the strip, whichare also formed of insulating material. Inthe form of my invided withregistering holes 17 in which the ""resistance" element 'is disposed. Inorder to insert the resistance element 'si'dewise into these holes,slits 18 are provided which extend from-the holes to the lower edge'ofthe strips and in order to lock the resistance element in position, theslits in the two pieces leading to the opening are angularly arranged.Ihstea'd of arranging the slits in thestrip at the lower edge of thepiece as just described, they may be arranged in the upper portion asshown in Fig. 6. In order to prevent any liquid or other material thatis being treated on the plate; from coming into contact with the memberswhich support the resistance element, flanges 19 are provided beneaththe plate at the inner and outer portions of the supports from which theliquid may drip. r

Figs. 7 and 8 show a modified arrangement in which each of the twostrips of mica are formed with reversely arrangedslots 20, the innerholes of which are curved and are armed with semi-circular metal "guards21.

The arrangement is such that after the convolutions of the resistanceelement have been placed in the slots when the strips of .mica

are apart, the strips are then brought to-.

gether with the slots registering as shown in Fig. 8 andcircular metallined holes will be. provided for supporting the convolutions ofconductor, the adjacent guards 21 forming, in effect, a series of metaleyelets. One pair of strips of mica and two lengths of mica wedges maybe used for each rib as already described in connection with Fig. 2 orseveral lengths of strips 14 and several lengths of mica wedges may beused for each rib as shown in Fig. l. The terminals for'the'heating unitare indicated by the reference characters 22, 23, 24 and 25 which areconnected to conductors 26, 27, 28 and 29,respectively.

While I have described my invention as embodying a concrete structureand as operatingin aspecific manner in accordance with the provisions ofthe patent statutes, it should be understood that I do not limit myinvention thereto, since various modifications thereof will suggestthemselves to those skilled in the art without departing from the spiritof my invention, the scope of which/isset forth in the annexed claims.

Vhat I claim as new and desire to secure by Letters Patent of the UnitedStates, is: 1. An electric heater comprising a bare resistance element,means carrying said element, and a metal plate provided with openingsseparated by ribs covering said means.

2. An electric heater comprising a bare,

resistance element, means carrying said element, and a metal plateprovided with openings separated by ribs supporting and coveringsaidmeans.

3. An electric heatercomprising a metal plate provided with openingsseparated by ribs vertically disposed, insulating strips secured to theunder side of s'aid ribs and formed with holes, and a bare resistanceelement disposed within said holes, the ribs covering said insulatingstrips.

4. An electric heater comprising a metalance element disposed withinsaid holes, the

insulating strips being provided with slits extending from said holes tothe edge ofthe strips by which the resistance element may be insertedwithin the holes.

6. An electric heater comprising a metal plateprovided with openingsseparated by ribs, a bare resistance element carried beneat the plate bysaid ribs and insulated therefrom and flanges secured to the under sideof the plate adjacent to the resistance element.

In witness whereof, ll -havehereunto set my hand this sixth day ofDecember, 1917.

ARTHUR FRANCIS BER-RY.

